How to print out a stencil
T-shirt printing w/ stencils on freezer paper
T-Shirt Printing with Screen-Printing Ink

Multi-color printing on a red t-shirt (Aggrolites design 2 color)
Multi-color printing on a white t-shirt (Anti-Nazi symbol - 3 color)
Multi-color printing on a white t-shirt (Anti-Fascist Flag symbol - 2 color)
Multi-color printing on a white t-shirt (Cock Sparrer logo - 2 color)
Multi-color printing on a black t-shirt (Defects design 2 color)
Multi-color printing on a black t-shirt (Musfits design 3 color)

OneLegOut.com has a detailed tutorial for stenciling, both for printing and graffiti purposes.